Strange warning buzzer pattern

[onehunglow]

I have a 1987 Evinrude 70hp with the VRO. Normally there are 3 warning buzzer patterns...steady means overheat, 1/2 second on-off means no oil and a 1/2 second every 30 seconds mean low oil.

But the buzzer is making a short buzz every 5 seconds continuously. But its a very short buzz....probably shorter than 1/4 second...very quick and low buzz..almost inaudibly but continuous.

heat and oil are all okay

what could that be?

 

[jonesg]

Re: Strange warning buzzer pattern

The buzzer has 3 wires,

purple v+
Black neg-
Tan signal wire.

Remove the tan signal wire from the buzzer,
if it keeps buzzing the buzzer is no good and needs replacing.

 

[boobie]

Re: Strange warning buzzer pattern

You also have an unregulated charging system on your mtr. Sometimes high voltage in the system can also cause the alarm buzzer to do weird things.

 

[seahorse5]

Re: Strange warning buzzer pattern

The first thing to do is disconnect the oil tank to engine wires at the motor. The electronics inside the oil tank pickup go bad quite often and will give weird sounds.

If that doesn't stop them, disconnect the black wire at the horn. That is only used for the "self test" beep when you turn the key to on. If the sound goes away, chances are the electronics inside the horn were bad.

 

[onehunglow]

Re: Strange warning buzzer pattern

I had changed out the VRO tank with a newer one (spare I had) thinking that it might have been the float or sensor inside....but its the exact same problem. Its a little "chirp" of the buzzer...

One post says that voltage might be the culprit...I am getting the 12-16 volts or so when the engine is running (yes I know its unregulated) - can this cause the buzzer to sound like this?

Also the sensor for "low oil" is in the float mechanism in the VRO, I understand that, but is the "NO OIL" in the VRO or is it at the fuel/oil pump in the motor?

 

[d.boat]

Re: Strange warning buzzer pattern

I had changed out the VRO tank with a newer one (spare I had) thinking that it might have been the float or sensor inside....but its the exact same problem. Its a little "chirp" of the buzzer...

One post says that voltage might be the culprit...I am getting the 12-16 volts or so when the engine is running (yes I know its unregulated) - can this cause the buzzer to sound like this?

Also the sensor for "low oil" is in the float mechanism in the VRO, I understand that, but is the "NO OIL" in the VRO or is it at the fuel/oil pump in the motor?

Just to keep the terms straight: The "VRO" IS the fuel/oil pump. When you' say "the VRO" you are referring to the pump.

The oil tank is the oil tank, not "the VRO".

[took out link to VRO pump diagram.... but it's in this article:

http://continuouswave.com/whaler/reference/VRO.html

 

[onehunglow]

Re: Strange warning buzzer pattern

my apologies... to me the VRO is the whole SYSTEM

yes I meant I changed the oil TANK ...and I am wondering if the "no oil" sensor is part of the pump (which is what mixes the oil with the gas). How does that sensor work? When the oil stops flowing it sounds? When people remove their VRO system, all the do is plug up the oil line...how do they stop the "no oil" sensor from going off?

 

[d.boat]

Re: Strange warning buzzer pattern

my apologies... to me the VRO is the whole SYSTEM

yes I meant I changed the oil TANK ...and I am wondering if the "no oil" sensor is part of the pump (which is what mixes the oil with the gas). How does that sensor work? When the oil stops flowing it sounds? When people remove their VRO system, all the do is plug up the oil line...how do they stop the "no oil" sensor from going off?

I think that article linked above explains how the no oil sensor works. I really don't understand it, but do know how to test it!

 

[boobie]

Re: Strange warning buzzer pattern

Two things I would suggest to do. 1, when the horn is chirping disconnect the wires going to your oil tank and see what happens 2, turn on all the accessories in the boat to drop the voltage in the system to maybe 13.8 volts. If this doesn't do it you may have a bad horn. OMC did have trouble with the oil tanks '95and prior with the electronics in them giving off false
signals.

 

[onehunglow]

Re: Strange warning buzzer pattern

Yes I hear you, but I had already switched out the oil tanks and no change. I had the electrical disconnected also from the 1st oil tank before changing it - same problem

Could the chirping be caused by 1) a VOLTAGE issue (too high or low?), 2) a TACH issue (either the circuit or the tach itself)? or 3) something happening in the VRO itself (there is some circuitry to detect a no oil situation)

 

[boobie]

Re: Strange warning buzzer pattern

The first thing I would do if I was working on it was temporalirly disconnect the electronics plug from the vro and see what happens. Next I would get the voltage down in the system by either putting a load tester on the battery or else turning the mtr over with the plug wires off and then re-starting to see what happens with the system voltage. Last I would replace the horn.

 

[clanton]

Re: Strange warning buzzer pattern

The no oil sensor is on the VRO pump. There is diode in engine harness to block false signals. Late model (1995) oil tank sensor is not compatible with early model systems. If you premix 50-1 and do not use the VRO for oiling, you have to disconnect the harness at the pump, and the wires at the engine for the remote oil tank. The horns had a high failure rate. The logic for the system self test and different beeps is on the horn. Disconnect tach when checking system.

Disconnect all sensors, horns still beeps replace horn.